The problem of maintaining the purity of aquarium water and of supplying proper aeration in order to sustain marine life therein has occupied the attention of numerous inventors and a substantial number of patents have been issued. Circulating the water through suitable external filters is a common expedient which, of course, is accompanied by many practical problems and the supply of aeration or oxygen has been treated in various manners in the prior art.
Applicant has received U.S. Pat. No. 4,272,372 for his aquarium with aerator and purifier construction and has overcome the prior art which is cited therein.
The patents to Kast and Bennett, U.S. Pat. No. 3,770,128, U.S. Pat. No. 3,891,555, are closest to applicant's former and present invention, which were both overcome in the prior patent, so that the only and closest outstanding art is that of applicant's previous U.S. Pat. No. 4,272,372 mentioned above.
Basically, the problem is one of continuously removing the impurities from the water in the aquarium, supplying proper aeration, and providing for frequent and easy renewal or exchange of the purifying media. Also of great importance is the creation of a dormant area in which algae-like material of biological importance to the marine life can flourish.
My previous invention covered a global aquarium with the filtration medium located at the top of the globe and means for circulating the aquarium water through the filtration apparatus, aerating it at the same time and providing for easy access for removal of the filtration media and renewal of same.
There are numerous types and forms of aquarium filters. One type of filter device is the undergravel filter. In such filters, the filter is placed under the gravel bed, using the gravel as the filtering media. Such prior filters suffer from several disadvantages, one of which is the accumulation of waste and debris imbedded in the gravel and soon thereafter requiring the hobbyist to place his hands within the aquarium water to remove the gravel in order to wash and clean it. Further disadvantages in the washing of the gravel are that the necessary algae bacteria important to the chemical process that converts waste products into non-toxic matter is also washed out with the gravel wash.
Other types of aquarium filters are the corner filters which are placed over the gravel and cartridge filtration devices. These have tended to be bulky and cumbersome, particularly with regard to the replacement of the filter medium and use of glass wool when packed too tightly and thus preventing sufficient suction within the tank, particularly when the inlet holes are not close to the bottom of the aquarium tank. Under these conditions the filter is unable to lift or suck up the larger sediment that settles at the bottom of the tank. Such aquariums are covered by U.S. Pat. Nos. 3,720,318 to Cohen and 4,148,730 to Willinger.